This invention relates to methods and apparatus for generating electrical, thermal or mechanical energy from the oxidation of aluminum or its alloys, especially from aluminum waste and other inexpensive aluminum products.
In my copending applications and prior patents, I have disclosed apparatus and methods for withdrawing electrical energy, heat, and an aluminum hydroxide reaction product from the electrochemical oxidation of aluminum, preferably in aqueous alkaline electrolytes. The present invention deals with apparatus and methods for generating mechanical or electrical energy from the oxidation of aluminum without necessarily resorting to aqueous alkaline systems or even to electrochemical energy conversion.
Electrochemical power sources usually necessitate a number of series-connected cells to provide the required voltage. Moreover, the electrochemical aluminum-consuming systems dislosed thus far usually necessitate electrolyte circulation through these cells, in which in turn introduces current leakage problems. The complexity of such series-connected systems increases their cost and may affect their reliability.
It is therefore an object of my invention to provide aluminum-consuming power sources which are simpler in design and operation, and cheaper to manufacture and maintain.
It is still another object of my invention to provide an aluminum-consuming power source having high overall energy storage and power densities.
In alternative embodiments of my invention, the energy conversion means is still electrochemical rather than thermal. However, it disclosed aluminum-consuming electrochemical cells in using a non-caustic or only mildly caustic electrolyte.
Non-alkaline primary aluminum batteries are known in the art. However, such batteries have utilized aluminum alloys of special composition.
It is yet another object of my invention to provide non-alkaline aluminum-consuming electrochemical cells which do not necessitate the use of special alloys.
It is still another object of my invention to provide aluminum-consuming power sources which can utilize disposable aluminum cans or other inexpensive forms of aluminum as their primary fuel.